1. Field of the Invention
The present invention relates to a continuously advancing track working machine for compacting ballast supporting a track comprised of two rails fastened to a succession of ties, each rail having a gage side and a field side, which comprises a self-propelled machine frame supported by undercarriages on the track for mobility in an operating direction, a track stabilization assembly vertically adjustably mounted on the machine frame between two of these undercarriages, the track stabilization assembly comprising drive means for vertically adjusting the assembly, oscillatory rolling tools arranged for engaging the rails, vibrating means for oscillating the rolling tools, and spreading drive means for pressing the rolling tools against the gage sides of the rails. The machine further comprises a track leveling reference system including a track level reference base having a leading and a trailing end point in the operating direction, and a measuring axle rolling on the track and carrying a pickup generating a track level indicating signal.
2. Description of the Prior Art
A dynamic track stabilizer of this type for compacting a ballast bed has been disclosed in U.S. Pat. No. 4,064,807, dated Dec. 27, 1977. The vertically adjustable track stabilization assembly runs on the track rails on flanged wheels whose flanges are pressed without play against the gage sides of the rails and laterally pivotal flat rollers are pivoted into engagement with the field sides of the rails to hold the track rails firmly while the assembly is vibrated to impart oscillations to the track in a substantially horizontal plane and a substantially vertically extending load is applied to the assembly by hydraulic vertical adjustment drives. The flanged wheels and the flat rollers constitute the rolling tools of the track stabilization assembly, and the track will be settled by condensing the supporting ballast under the static load while the machine continuously advances along the track. The track level is controlled by a leveling reference system comprised of two tensioned reference wires illustrated.
U.S. Pat. No. 4,046,079, dated Sep. 6, 1977, shows such a dynamic track stabilizer coupled to a track tamping machine. A conventional reference system extends along the track stabilizer and the tamping machine, and its tensioned reference wire is guided without play along the guide rail of the track to indicate and record the existing track position. Any deviations of the existing track position from a desired track position are corrected by lining drives which transversely displace the track. The reference system is aligned principally with respect to the tamping machine.
U.S. Pat. No. 4,643,101, dated Feb. 17, 1987, discloses a continuous action track working machine with an elongated two-part machine frame whose parts are hinged together. The leading machine frame part constitutes a track leveling, lining and tamping machine carrying an operating unit which is longitudinally displaceable relative to the machine frame. The trailing machine frame part carries two track stabilization assemblies and a vertically adjustable track sensing element is guided along the track between the two assemblies. A contact at the upper end of the track sensing element is associated with a tensioned reference wire of a leveling reference system associated with each track rail. A tensioned reference wire of a lining reference system extends centrally between the rails from the leading to the trailing end of the machine frame, and another track sensing element at the operating unit cooperates with the lining reference wire to control the lining operation.